<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Rect Rotation</title>
  <style>
    #speed {
      display: inline-block;
      width: 30px;
    }
  </style>
</head>
<body>
  <div id="controller">
    <select id="direction">
      <option value="1">逆时针</option>
      <option value="-1">顺时针</option>
    </select>
    速度：<span id="speed">20</span> <button id="speedUp">+</button>
    <input id="speedRange" type="range" min="0" max="100" step="0" value="20">
    <button id="slowDown">-</button>
  </div>
  <canvas id="gl-canvas" width="512" height="512"></canvas>
  <script src="/rotation_control/app.js"></script>
</body>
</html>